


Two Universes

by KileaMeagan



Category: Adventure Time
Genre: Adventure, F/M, Forbidden Love, Opposite Universes, Other Additional Tags to Be Added, Romance, Sexual Tension
Language: English
Status: In-Progress
Published: 2013-08-08
Updated: 2014-07-16
Packaged: 2017-12-22 19:31:56
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 3
Words: 3,646
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/917193
Author URL: https://archiveofourown.org/users/KileaMeagan/pseuds/KileaMeagan
Summary: <blockquote class="userstuff">
              <p>Marshall Lee finds himself in Ooo, the opposite universe to his, with only Marceline Abadeer to help him find his way back. But he soon falls for Marceline and finds himself stuck between going back to Aaa or staying with the girl he loves. To make matters worse, if Marshall and Marcy touch both of their universes might explode!</p>
            </blockquote>





	1. Hambo

**Author's Note:**

> I started writing this before Sky Witch came out so in this Hambo ended up being sold to a little shop somewhere in Ooo. You also have to imagine that Marceline was not the one who told the Bad Little Boy story. Hope you love it!

“Hey, that’s mine!” Marceline rushed over to the guy who was holding her precious childhood toy, Hambo. Her ex had sold it to a witch years back, but it must have ended up back in this little shop, and now in the hands of this stranger. “Give Hambo to me you freak!” Marcy snatched the toy from the guy’s hands and hugged it tight.

“Give him back!” The guy snatched the stuffed animal back from her. “How do you know his name?”

“Um, because he’s my childhood toy. I stitched him up when he fell apart, even-“

“Sewed his eye back on,” the man finished. “You’re a freaky stalker because _I _did all those things.”__

__Marcy scowled. “Who are you?”_ _

__“Marshall Lee, the Vampire King.” Marshall bowed._ _

__“Okay, you are so messed up in the head. There is no Vampire King.”_ _

__Marshall looked at Marcy like she was stupid. “And how would you know that?”_ _

__“Because,” Marcy tilted her head to the side so Marshall could see her permanent bite marks. “I’m the Vampire Queen. I would know.”_ _

__“What the-” Marshall looked at Marceline in wonder._ _

__“Can I just have my stuffed animal?” Marceline sighed. “This is getting too weird for my taste.”_ _

__“Wait, wait, wait. Who are you?” Marshall asked, holding the toy a little closer._ _

__With a sigh, Marcy replied, “Marceline Abadeer. Current Vampire Queen. And you are?”_ _

__“Marshall Lee, current Vampire King in the land of Aaa.”_ _

__“Wait, the land of Aaa? Dude, you have your vowels mixed up. This is the land of Ooo.”_ _

__Marshall scratched his head. “That would explain all the backwards-ness. And I did fall into a portal earlier.” Marshall laughed awkwardly._ _

__“Hey you know what that means?” Marceline didn’t wait for an answer. “That means this is my Hambo, not yours!” She grabbed Hambo and floated away._ _

__Marshall flew up beside her. “Hey! You have to help me get back to my universe or whatever.”_ _

__Marcy huffed. “I don’t have to help you do squat. Plus the sun’s coming up and I have to get home.”_ _

__Marshall paused to look at the sky that was minutes from blazing orange with the rising sun. He flew fast and caught back up with Marceline. “I’m coming with you then.”_ _

__“Whatever, I guess.”_ _

__*******_ _

__When Marceline arrived at her house the sun was just rising. A small ray hit her arm before she could get into the cave and she hissed in pain. “Ow! Glob that hurt.”_ _

__“You okay?” Marshall went to look at the burn but she jerked away._ _

__“Mind your biz, Marshall. It’ll heal.” She frowned at the mark as it faded away, slowly returning to normal skin. “If you’re coming then come on.” Marceline slid her key into the front door’s lock and opened her house. “Just don’t touch my stuff, okay?”_ _

__“Come on. You can trust me.”_ _

__Marcy let out a small laugh as she flew past him into the kitchen. “I just met you, guy. Like five minutes ago.”_ _

__Marshall shrugged in response, and went to float over the couch. He looked around at Marceline’s living room. Red couch, coffee table, no TV, and in the corner was a red Fender bass propped against the wall. “Cool bass,” he said, floating over to it. Just as he was about to pick it up Marceline poked her head out of the kitchen and hissed. “Don’t touch my stuff!” Marshall put his hands up in surrender._ _

__Marceline disappeared back into the kitchen and grabbed the two apples from her fridge she had been saving for a special occasion. They were from Tree Trunks’ apple trees and were a deep, shiny red – similar to the color of blood. Marshall was cute; it seemed a special enough an occasion._ _

__Marcy hovered back into the living room. Marshall was sitting on the couch looking bored. “Hungry?”_ _

__Marshall looked up and smiled, flashing his fangs. “Starving.”_ _

__Marceline underhanded the apple to him and sat down on the other end of the couch. “Sorry, but I only drink shades of red. This color is the closest to blood in color and flavor.”_ _

__“Thanks. Actually, I drink red too.” He sunk his fangs into the apple and drained it of color until it was just a grey husk. Marceline watched him and got caught up in how sexy he was. His jet black hair fell onto his face and when he pushed it back behind his ear she almost sighed._ _

__Instead she caught herself and coughed awkwardly. “Not hungry?” Marshall asked, pointing at her still red apple._ _

__“Oh, no. I mean yeah.” Marceline copied Marshall’s actions and drank all the red from her apple._ _

__What she didn’t know was that Marshall was feeling the same way she was. He did let out a sigh as Marcy ran her hand through her ultra long black hair. She was just so beautiful. He wanted to run his fingers through her hair, too._ _

__“What are you looking at?” Marcy said defensively, making Marshall blush._ _

__“Sorry, I was just… um… wondering how I got here. Where is here anyway?”_ _

__“Well, this,” Marceline gestured around herself, “is my house. But if you mean more generally, then this is Ooo.”_ _

__“I get that, but what I don’t get is how it exists. I mean it’s completely backwards compared to Aaa.” Marshall shook his head in confusion. “Tell me more about Ooo.”_ _

__Marcy went on to explain the history of Ooo and her history as well. Every once and a while Marshall would point out the similar events in his or Aaa’s history. She also explained Finn and Jake’s role in Ooo._ _

__“They basically protect Ooo from whatever and go on adventures and stuff. They are like my only friends,” she said with a sigh._ _

__“Sounds like Fi and Cake. They love adventures. Fi has a thing for swords.” Marshall laughed quietly. “They are basically my only friends, too. Cake holds a grudge ‘cause I kidnapped her once, but we get along.”_ _

__This made Marcy smile. “I think Finn is still a little upset that I kicked him out of his house once.”_ _

__“I made Fi really mad once and she threw a spear at me.” They both went silent and then burst into laughter._ _

__After they calmed down from laughing so hard Marshall asked: “So, is Finn dating anyone? Because Fi is available.”_ _

__“Nah. He’s dating Flame Princess. And he also has a thing for Princess Bubblegum.”_ _

__“Princess Bubblegum? Who’s that?”_ _

__Marcy rolled her eyes. “She’s Miss Perfect Princess of the Candy Kingdom.” She stuck her forked tongue out._ _

__“Sounds a lot like Prince Bubba Gumball. He’s Aaa’s biggest royal snob.” Marshall stuck his forked tongue out as well._ _

__Marshall and Marcy talked for about half an hour just about the ‘royal snobs’ of the Candy Kingdoms. Then, Marcy let out a big yawn._ _

__“Tired?” Marshall asked._ _

__“Yeah, it’s like waaaay past my bedtime.” Marceline stretched like a cat and yawned again. “Feel free to sleep on the couch. Tomorrow I’ll help you find your way back to Aaa.”  
Marcy levitated her way up to her bedroom and flopped onto her bed. _I don’t want him to go back _, she thought.___ _

____Downstairs, Marshall was lying across the couch with his hands behind his head. He closed his eyes and tried to dream but all that was going through his mind was _I don’t want to go back _.___ _ _ _


	2. Emotions and Junk

**Notes for the Chapter:**

> I'm soooooo sorry this took so long for me to write. I was on a serious I'll never write again hiatus. Luckily, I decided that was stupid because I love writing. So here you go! I hope you enjoy!

Marcy woke up to the sound of her bass guitar being played. She had very sensitive hearing and knew her instruments well. She shot up out of bed so fast she almost hit the ceiling. She was all the way to the ladder that led down to her living room when she remembered Marshall. _He must be playing it. Whatever. It’s too early for me to care._ She turned and caught a glimpse of herself in the mirror. _Yikes. Shower time._

Marshall was sitting on, or rather floating slightly above, the red leather couch strumming the red Fender bass. He was okay on bass, but it wasn’t his favorite. He tried to pick out the notes to Bad Little Boy, but gave up. He put the guitar back on the wall, flopped back down on the couch, and sighed. _I wonder what Fiona is up to right now? Probably laying down after a long day of saving Aaa. Or polishing her sword while cake makes dinner._

Just then Marceline came down from her room with a towel wrapped around her head like a turban. Her cheeks were still flushed a little from the hot water, but when she saw Marshall laying across her couch with his hair and clothes rumbled they lit up. He had his eyes closed and hadn’t noticed her so she took the towel from her head and tossed it at him.

“Hey! Good morning to you, too,” Marshall said sarcastically. He blushed a little as she shook out her onyx hair. _Glob, she’s beautiful._ Embarrassed by his face’s betrayal of is feelings, he rubbed at his cheeks, and by the time she looked up the flush was gone.

Marceline squinted at Marshall’s strange expression, shrugged, and then floated into her kitchen. She grabbed a couple strawberries and sucked the red from them. Then she grabbed a couple more and floated back to Marshall. He stood up as she dropped them in his hand.

“Thanks,” he said after they had been drained of their color.

“You should go take a shower. It’s in my room up there,” she pointed to the ladder. “I laid out some clothes for you that should fit if you want to change,” Marceline stated in a very matter-of-fact voice. Marshall nodded and floated up the ladder. When he was gone Marcy sighed and went back into the kitchen to grab her phone, which was shaped like a demon-fish, and dialed Finn’s number.

“Hola, vampire lady,” Jake answered sleepily. “What’s,” yawn, “up?”

Marceline smiled evilly. “Did I wake you from your slumber?” Marcy hissed the last word. She loved messing with Jake because he used to be scared of her.

Jake chuckled heartily and said, “Uh uh, Marcy. You can’t scare me anymore.”

Marceline laughed lightly. “You’re right.”

“Hey, look Marceline, as much as I love talking to you in the middle of the night for no reason, did you actually have a point in calling me?”

“Yeah,” she sighed. “I need your and Finn’s help. I have a… situation.”

“Well, if it’s more ghosts I’m out.”

“No. Not ghosts. Weirder than that. But less dangerous. I think.”

Jake yawned again. “Okay. Just let me wake Finn up real quick.”

Marceline heard Jake put his hand over the phone and yell.

 

_“Finn! Wake up!”_

_"Uhhhg.”_

_"Finn! Guess what time it is!”_

_“Midnight?”_

_“No, man. It’s ADVENTURE TIME!”_

 

She heard some rustling, and then Jake was back. “He’s up. We’ll be over in no time.” He hung up, and Marceline did the same.

Setting her phone down on the kitchen table, Marceline decided to go tell Marshall about Finn and Jake coming to help. She floated out of her small kitchen, through her living room, and up the ladder. When she got to the top she stopped short. There was Marshall, facing the opposite way, wearing nothing but boxers. _Woah_ , she thought.

Marshall was not paying attention. He was lost in thought – about everything from Marceline to crème puffs. His mind had been swirling in circles since he had gone to sleep. Or rather tried to. He wasn’t that successful.

Marceline was paying attention. Marshall Lee was – to put this eloquently – a hottie. He was lightly muscled. Nothing too defined, just enough to be proportionate with his tall, thin frame. His skin was a pale color somewhere between sea foam and shark skin, which contrasted perfectly with his shoulder length black hair. As he slid on the black skinny jeans, grey tank, and red flannel shirt Marceline had laid out for him – which fit astonishingly well for being girl’s sizes – she tried to get herself together.

Where had the witty, confident Marceline gone? Was she really going to be reduced to a drooling idiot because of some hot stranger? _No. I’m not some teenage girl. I’m 2000 years old. I’m the Vampire Queen_. She repeated this mantra a couple times before she spoke.

“Nice hot cakes, bro.”

Marshall whipped around and saw Marceline floating up out of the hole that led up to the bedroom. “Oh my Glob, Marceline! What the stuff?”

She laughed and floated over to her bed. She flopped down and scooped up Hambo, who was leaning against her bedside lamp. “Oh, come on Marshall. Don’t get all messed up. I wasn’t spying on you. I just came up here to tell you that Finn and Jake are on their way over to help us figure our situation out.”

Marshall sighed and ran his hand through his hair. “It’s cool. Sorry I flipped. I guess I’m just jumpy.” He looked down at the flannel shirt he had just buttoned half way. “Thanks for the clothes, by the way.”

“No prob.” Marceline smiled as an idea crept into her head. She levitated off the bed with Hambo and floated over to stand close to Marshall. She leaned in slowly until Hambo was pressed up against both of their chests. Marshall’s eyes got wide, and he opened his mouth, but nothing came out. She leaned into his pointed ear and whispered, “It’s my pleasure.” She paused and then backed away quickly to see his confused face and cackled.

Marshall felt his face fall. _What was that about?_ As Marceline’s laughter died down, Marshall’s frown deepened and his cheeks reddened. _She knows I like her, and she’s playing with me._

Marceline’s laughs died off when she looked at Marshall. He was red faced and angry. “Hey, calm down. It was a joke, Marshall. No reason to get angry.” She went to put her hand on his shoulder, but he just shrugged away from her.

“That was messed up, Marceline. It’s not cool to play with people’s emotions and junk.”

Marceline sighed. “Sorry, Marshall. Emotions are fun to mess with, though. Tell me you’ve never done it.”

Immediately he thought of Fiona, and how he had messed with her feelings. It was fun at the time, but Fi had hit him hard with a truth bomb, and he realized how mean it was. “I used to do it all the time. Then someone really important showed me how much it hurt her, and I promised to never do it again.”

A loud knock and shouts of Marceline’s name broke up their conversation. Marshall looked at her and shook his head, then sunk down through the hole to the living room. With a sigh, Marcy followed.

**Notes for the Chapter:**

> Chapter 3 should be posted soon (fingers crossed). I promise there will not be that big a gap between posts again, but I don't have an exact time frame. Sorry.


	3. Finn & Jake

**Notes for the Chapter:**

> Sooo I wrote this in a single night. I hope it's good. I went from total writer's block to word vomit in 2.5 seconds. I hope you guys like it!

Marceline was reaching for her doorknob when the door flew open. Finn rushed in and flung himself onto Marshall, who was standing behind her. Marshall started to hiss and scratch at the attacking boy. Marceline quickly grabbed Finn and threw him against the wall.

“Finn, stop!” She bared her fangs and hissed at him. “What are you doing?”

“Ummmm…,” he said as he stood up and scratched his head. “Saving you?”

Marceline’s fangs retracted and she rolled her eyes. She turned to Marshall to see him standing up slowly. His fangs were also gone now, but he still looked like he wanted to fight someone.

“Are you ok,” she asked as she reached out to him. He hissed at her and backed up. Marceline sighed. He was furious. The 24 hours he had spent in Ooo so far had been some of the worst in his 2000 years. This was icing on the cake.

Marceline turned to close the door. Jake was still standing on her porch holding a coffee cup. “May I come in?”

“Sure.”

He walked inside her house and she shut the door. Turning her back and shutting her eyes, Marceline slid down to the floor. Marshall suddenly noticed how tired she looked. He wanted to reach out and help her get up, but thought better of it. _She doesn’t like you. She was just playing with you._

Marceline opened her eyes and stood back up. Finn was still against the wall, Marshall had his arms crossed, and Jake was sliding his empty coffee cup into Finn’s backpack. “So, Marcy, you said you needed our help?”

“Yeah, Jake. Why don’t you two sit down, and I’ll explain.” They settled down on her couch, while she sat with her legs crossed on the floor facing them. Marshall sat down with a huff in her arm chair beside the door.

“Finn, I would like to introduce Marshall Lee. He’s from an opposite world thing called Aaa. He probably doesn’t like you.” Marcy waved toward Marshall, who was pulling at the loose threads on the buttons of his shirt.

Finn blushed. “Sorry, bro. I thought you were attacking Marcy.”

“Yeah, well, I wasn’t,” Marshall mumbled angrily.

“He’s sorry, man. He gets a little poo brain sometimes,” Jake said.

“Whatever. I’m over it.”

Marceline pulled at the ends of her hair. This was so stressful. “Bigger problems, dudes. Number one being that Marshall needs to find a way home.”

Jake rubbed his chin. “Well, how did he get here?”

Marceline looked over at Marshall to see if he was going to explain, but he was slowly tearing the buttons off of his shirt. It looked like she would have to explain. “Some kind of portal, I think. Probably something made by a wizard. I met him at a shop where I found Hambo.”

“Where was the portal? Maybe he can just hop back through,” Finn suggested.

“It disappeared as soon as I went through it,” Marshall answered.

“Crud buckets. Maybe Peebs can help us.”

While Marceline didn’t like the idea, she couldn’t help thinking he was right. The Princess would probably know how to get Marshall back. She stood up and pulled down the big t-shirt she was wearing. It fell off her shoulders and was long enough to be a dress on her. “Then let’s go see Bonnibel.” She looked down at her outfit. “Let me put on some pants first.”

Finn and Jake nodded and headed toward the door. “We’ll be outside,” Jake said.

Marceline started up the ladder to her room, but stopped to look at Marshall. “I’ve got a couple different umbrellas. Come pick one out.” He got up and followed her up into her room. Marceline opened her closet doors and pulled out her umbrellas. “Here.” Marshall took them and laid them on her bed.

Marceline pulled a pair of blue skinny jeans off a hanger. She slipped them on and then put on her tall brown boots. Marshall watched her as she snapped the buckles in place. She was already tall, and the boots’ heels made her even taller than him. The jeans she had on were fitted like a second skin.

“Hey, turn around. I’m gonna change my shirt.” Marshall nodded and turned. He heard her shirt slip over her head and couldn’t help but look. Her bra was black and lacy. Her skin was the lightest blue grey he had ever seen. She slipped on a grey crop top that left her lower back exposed.

Marceline closed her closet and turn to see Marshall staring at her. She looked down at her shirt. It had a red anti-smoking symbol on it and stopped just above her navel. “What?”

Marshall looked away and coughed uncomfortably. “Nothing.”

Marceline frowned and pointed to her bed where the umbrellas sat untouched. “Did you pick one?”

Marshall looked at the umbrellas and picked up a black one that had a bone handle and looked like it was make out of leather. He held it up. “This one.”

“Okay,” Marcy said. She floated by him and grabbed a navy blue umbrella with a skull speared on its tip. “Come on.”

They both floated down to the door and stepped out, holding their umbrellas. Finn and Jake were sitting on the porch beat boxing. They stood when they heard the door open.

“You guys ready?” Finn and Jake both nodded. Jake then stretched and grew until he was as big as Marcy’s house. Finn crawled up his tail onto his back. Marshall followed Marceline as she floated up to sit on Jake’s back. They all three sat with their legs under them as Jake slowly took off toward the Candy Kingdom.

“Why do you guys have umbrellas,” Finn questioned.

Marceline laughed lightly. “Because Finn. We’re vampires. Duh.”

“No, I get that, but it’s like midnight. You guys won’t need those for hours.”

“Finn, it’s almost 4 a.m.”

Finn scrunched up his face. “Hmmm. Why did I think it was midnight then?”

“Because you have no sense of time, brother,” Jake chimed in. “You always think it’s midnight when it’s dark.”

“Oh, yeah. I do do that, don’t I?” He sighed. “Oh, well. To the Candy Kingdom!”

Marceline smiled a little. Finn was so young and naïve, but he was so fun. He made her feel young again too.

Marshall watched as Finn walked up Jake’s back and onto the top of his head. He had pulled out his sword and was standing in a ‘hero pose.’ He could see Fiona doing the same thing on Cake. It made him miss Aaa again. He wanted to go home so badly. However, his unbeating heart was burning in his chest with a need to stay. To be with the vampire girl beside him. To spend his infinite days figuring her out. It made him mad. _She doesn’t like you. And she played with you and laughed in your face._

He growled and picked violently at his shirt buttons. There were only three left, and by the time Jake yelled, “We’re here!” those were gone too.


End file.
